1. Field
Some example embodiments may relate to control methods of single-port surgical robots that enable intuitive manipulation like that of multi-port surgical robots.
2. Description of Related Art
Minimally invasive surgery refers to surgical methods to reduce or minimize the size of an incision. Differently from laparotomy using a relatively large surgical incision through a part of a human body (e.g., the abdomen), in minimally invasive surgery, after forming at least one small port (or incision) of 0.5 cm˜1.5 cm through the abdominal wall, an operator inserts an endoscope and a variety of surgical instruments through the port, to perform surgery while viewing an image.
As compared to laparotomy, minimally invasive surgery has several advantages, such as reduced need for pain medication before, during, and after surgery, ability to use reduced strength and/or non-addictive pain medications, low pain after surgery, early recovery, early restoration of ability to eat, short hospitalization, rapid return to daily life, and superior cosmetic effects owing to a small incision. Accordingly, minimally invasive surgery has been used in gall resection, prostate cancer, and herniotomy operations, etc., and the use range thereof continues to expand.
In general, a surgical robot used in minimally invasive surgery includes a master device and a slave device. The master device generates a control signal corresponding to doctor manipulation to transmit the control signal to the slave device. The slave device receives the control signal from the master device to perform manipulation required for surgery of a patient. The master device and the slave device may be integrated with each other, or may be separately arranged in an operating room.
Surgical robots and associated systems provide numerous other advantages, such as potentially improved precision, better ability to monitor the patient, and ability to record the surgical procedure for training, qualification, and evidentiary purposes.
Examples of surgical robots include a multi-port surgical robot that forms a plurality of incisions in the body of a patient to insert a plurality of surgical instruments through the respective incisions in a one-to-one ratio, and a single-port surgical robot that forms a single incision in the body of the patient to insert a plurality of surgical instruments through the single incision at once. Here, the single-port surgical robot forms a single incision differently from the multi-port surgical robot and has been in the limelight owing to advantages of the narrow incision and early recovery.
However, since a plurality of surgical instruments is inserted through a single incision to perform surgery, single-port surgery is more limited as to movement of the surgical instruments as compared to multi-port surgery. That is, a single-port surgical robot may be controlled to move only within a conical workspace, an apex of which is a virtual incision center (that may or may not be predetermined). The virtual incision center is referred to as “Remote Center of Motion (RCM)”. Under coincidence of the remote center of motion and the patient's incision, surgical instruments inserted into the patient's body are moved only within the conical workspace even if movement occurs at robot arms located outside the incision, which may prevent the incision into which the surgical instrument has been inserted from being damaged due to movement of the robot arms.
During surgery using a plurality of surgical instruments inserted through a single incision, shafts of the surgical instruments may need joint functions like the wrist or elbow such that end effectors of the respective surgical instruments are oriented toward a specific surgical region without a risk of collision therebetween to assist an operator in manipulating the end effectors as if the operator were performing surgery by hand.